A variety of factors is propelling the shift, everything from the Paul Simon effect - a reference to the popular late Democratic senator, elected by typically conservative downstate voters - to the lack of a Republican presence in Chicago, where just 1 out of 50 aldermen is from the GOP.
But perhaps most important, there's the steady trend leftward in the suburbs. Indeed, for much of the past century, Illinois was the prototypical swing state because of the ring of humanity around Chicago. While the Democrats dominated in urban Chicago and the Republicans downstate, the suburbs ended up playing referee. They still do, but with rising numbers of Democrats in what were once Republican strongholds.
"The mix has stayed pretty much the same in the city and downstate, but in the suburbs it's gone from being overwhelmingly Republican to being more competitive," says Dick Simpson, a political scientist at University of Illinois-Chicago and a former Chicago alderman.
The city, too, has been changing. Long a manufacturing hub, the City of Big Shoulders now has twice as many professionals and technicians as production workers. Instead of being a big brother to Kansas City or Detroit, Chicago now has a service-sector cosmopolitanism that makes it the heartland's biggest answer to coastal cities like San Francisco. Ruy Teixeira, coauthor of "The Emerging Democratic Majority," calls greater Chicago an "ideopolis" - a metropolitan hub with culture and diversity, where fewer people now pack meat and more practice law or perform in theaters. An economy oriented toward the production of ideas "tends to be fairly liberal, especially on social issues," he adds. Now "those kind of voters really set the tone in a lot of the suburbs."
Consider Monica Frigo, a young clerk who's lived in suburban Park Ridge for 19 years. She remembers when her family was the only one in her neighborhood with a Clinton/Gore sign out front. Now, Democrats "are starting to come out of the woodwork," she says, handing out Kerry/Edwards stickers at a town art fair. Plenty of residents are taking her stickers, including ones that say: "Republicans for Kerry."